My 1st noob log. 95 Gmc

[vandura95]

This van is a 1995 GMC that has over 150,000 miles on the odometer.
my ecm
http://www.gearhead-efi.com/Fuel-Injection/attachment.php?attachmentid=6924&d=1397250470

Will you please tell me how to interpret these logs.

The codes are
15 coolant sensor low
22 tps
33 map high
42 ignition error
43 knock sensor circuit failure

The Fuel looks like it is lean. 13.7

This is my first time....

[uhlhazard]

I've always wondered why they have afr readings. I'm not sure it's even possible for the o2 sensor to give any specific reading other than stoich 14.7 or lean/rich.

[steveo]

probably they put the open loop's target AFR in the datastream.


The Fuel looks like it is lean. 13.7

13.7 would be rich, not lean, but that AFR value probably doesn't mean anything.

[buddrow]

This van is a 1995 GMC that has over 150,000 miles on the odometer.
my ecm
http://www.gearhead-efi.com/Fuel-Injection/attachment.php?attachmentid=6924&d=1397250470

Will you please tell me how to interpret these logs.

The codes are
15 coolant sensor low
22 tps
33 map high
42 ignition error
43 knock sensor circuit failure

The Fuel looks like it is lean. 13.7

This is my first time....


Concerning the dtc's, I would look at ground wires, making sure they are getting good contact. They may share a common ground which could throw all those codes.

Buddrow

[uhlhazard]

There are several grounds on the back of the engine head on the 4.3 vin W. Mine had 2 with rat chew marks and another soaked in oil so the insulation was spongy. Ended up replacing them all.

On other GM vehicles I have worked on there are grounds that go to the thermostat housing. Thats an easy one to check too.

[buddrow]

Double check the wiring diagram sensor grounds, also check the ground at the ecm connector. If the grounds are solid the next check is the supply voltage to the associated sensors. Should have a 5 volt reference voltage supplied to the tps, cooant temp, map sensors. If there's not 5v ref voltage start at the ecm and work your way to the sensors.

Buddrow

[vandura95]

I know of the two grounds on the thermostat housing, I cleaned them and added electric grease.
I have located 3 ground wires on the rear of the block attached to the transmission bolt there is some missing insulation on the wire and I could see the strands of wire. I cleaned them and greased them prior to the log.
There is also a braided cable at the rear of the block. I will solder new terminals on all these wires. I will check the ground at the ECM, which will be very difficult in the conversion van.
Are there any other ground concerns I should search out?

There was no SES light or codes when I checked with the "paper clip"
I was only aware of these codes after I ran Tuner pro5.

I checked the TPS with a volt meter prior to the log.
If I unplug the knock sensor or the temp sensor the CES light will indicate this and illuminate.

"Stevo 13.7 would be rich, not lean, but that AFR value probably doesn't mean anything."
Now I know the smaller number equates to a richer mix.

[uhlhazard]

Hey vandura, noobie myself I wanted to know how you got codes out of tuner pro? I use my scanner (actron) but loaned it out.

[vandura95]

Hey vandura, noobie myself I wanted to know how you got codes out of tuner pro? I use my scanner (actron) but loaned it out.

This is how I got started.
http://ls1tech.com/forums/lt1-lt4-modifications/1298009-tunerpro-rt-v5-tutorial.html

[uhlhazard]

Okay so you are using the "item lists" and finding the codes there? Also do you have an emulator and what ecu does your 95 run? I'm rocking a 427 luckily.

[vandura95]

Okay so you are using the "item lists" and finding the codes there? Also do you have an emulator and what ecu does your 95 run? I'm rocking a 427 luckily.

Yes the list view is were I found the codes.

I do not have an emulator I was going to use the
burn2 and the adapter after I figure out how to get the other issues repaired.

The GMC van has the 16197427
I am still a long ways from a new tune.

I noticed the o2 sensor reading was jumping a lot, although I have nothing to compare it to.

[uhlhazard]

I'm using the moates autoprom and it is well worth the money. Burning chip after chip got to be pretty frustrating for little changes here and there. You don't happen to be in the south texas area? I'm about an hour north of Houston. The o2 sensor will should go up and down pretty consistently. If you see flat spots it might be time for a new one.

My setup is a little more advanced than stock. I run a wideband o2 that feeds a simulated narrowband reading to my ECU.

[vandura95]

I'm using the moates autoprom and it is well worth the money. Burning chip after chip got to be pretty frustrating for little changes here and there. You don't happen to be in the south texas area? I'm about an hour north of Houston. The o2 sensor will should go up and down pretty consistently. If you see flat spots it might be time for a new one.

My setup is a little more advanced than stock. I run a wideband o2 that feeds a simulated narrowband reading to my ECU.

Will you look at my log and give some thoughts.
I will be in sw. Missouri in a couple of weeks.

[uhlhazard]

Way too far to meet and use my emulator! Will check it out, be my first time reading someone elses logs. Fingers crossed!

[uhlhazard]

Running the first one it says you are sustaining 116mph and in 65th gear. What xdf are you using?

[vandura95]

Running the first one it says you are sustaining 116mph and in 65th gear. What xdf are you using?

Advanced $0D.xdf
From the tunerpro download page

[uhlhazard]

Alright, so I went to the tunerpro download page and I don't see any $0d listed for a van only $0e.

I just copied/pasted what matched your ecu under $0d. They don't say it's for a van but I'll try those and see if it works.




$0D


16197427


0D_tpv4_v200.xdf
(http://www.tunerpro.net/download/bindefs/GM/0D_tpv4_v200.xdf)V5 ONLY -0D_tpv5_v250.xdf (http://www.tunerpro.net/download/bindefs/GM/0D_tpv5_v250.xdf)



0D.ads (http://www.tunerpro.net/download/datastreams/GM/0D.ads)
V5 ONLY -
A217_0D_v250.adx
(http://www.tunerpro.net/download/datastreams/GM/A217_0D_v250.adx)A218_0D_Trans1_v250.adx
(http://www.tunerpro.net/download/datastreams/GM/A218_0D_Trans1_v250.adx)A218_0D_Trans2_v250.adx (http://www.tunerpro.net/download/datastreams/GM/A218_0D_Trans2_v250.adx)


94-95 C/K 4.3L, 5.7L & 7.4L

[uhlhazard]

HA! Got it working, I needed the correct ADX file. Alright lets see what I can find!

[buddrow]

Here is the xdf I use for $OD. http://www.gearhead-efi.com/Fuel-Injection/attachment.php?attachmentid=3947&d=1361028399 It works fine without any bugs that I have come across.

Buddrow

[uhlhazard]

Your O2 seems like it doesn't work at all staying around 500mv fir the first 3/4 of the drive2.xdl The cross counts are very low, iirc they should be 128 or so The knock counts of 309 is strange too. First thing I'd check is KOEO watch your datalogger and go from 0-100% throttle and make sure the sweep is correct. There shouldn't be ANY deviation. IF that works after 3-4 tries you can isolate out the tps sensor.

What is the history of this vehicle? That is just a lot of codes for having multiple failures. It has to be some electrical gremlin somewhere.

[vandura95]

Your O2 seems like it doesn't work at all staying around 500mv fir the first 3/4 of the drive2.xdl The cross counts are very low, iirc they should be 128 or so The knock counts of 309 is strange too. First thing I'd check is KOEO watch your datalogger and go from 0-100% throttle and make sure the sweep is correct. There shouldn't be ANY deviation. IF that works after 3-4 tries you can isolate out the tps sensor.

What is the history of this vehicle? That is just a lot of codes for having multiple failures. It has to be some electrical gremlin somewhere.

The history of the van is unknown.
The van is a conversion from a vender and sold new. There was a non functional alarm system tied into the starting system and maybe more.

I replaced the egr with a Negative pressure egr and I Installed a non heated universal O2 sensor from Autozone, I am going to re-install the heated unit and see if acts different on the log.


I have checked the TPS with the volt meter and while hooked up to Tunerpro5 and the sweeps look smooth to me.

"First thing I'd check is KOEO watch your datalogger and go from 0-100% throttle and make sure the sweep is correct." Please explain KOEO

To update this thread I will need to check my grounds and check the voltages at the sensors. I should re-install the heated O2 sensor too and re-log.

[uhlhazard]

They switched to heated o2 sensors because of how long certain setups' can take to get warm. An o2 sensor is useless until it gets to a certain temperature. The longer it is too cold the worse your emissions/fuel economy are. Also don't run a bosch o2 sensor. Hit a JY if you have to or rockauto.com for an acdelco o2 sensor. ebay isn't bad either.

I'm not familiar with egr's unless they are the electronic linear version the 4.3 w's have.

KOEO is Key On Engine Off. Volt meters are nice but you really need a histogram. The closest you can get is watching the throttle position values in TP. The neighbors and your engine might not like being held at 75% and higher throttle in idle testing the tps so most people tend to do it with the engine off.

For no history I'd just fix what you know is broken. Stick with delco parts, will save you tons of troubleshooting/headaches in the long run. Do you have a mechanical vacuum gauge? That would be a very nice test just to get a feel for how the engine is performing. I'd like to see +- 19inches at hot idle with the ac off. The readings can vary depending on elevation.

[vandura95]

My old vacuum gauge show about 15 steady at idle it will drop with increased throttle then return to 15.
While driving under light load it will drop and hold steady at -+ 10. Heaver throttle and on hills it will drop to 5.
I will need to verify my gauge is working and go from there.

Will low vacuum affect the MAP?

[ony]

I would clear all the codes and see which ones come back first. then start from there.

[uhlhazard]

Agreed with ony.

If 15 is normal for your elevation, check the needle for any bouncing/ticking. You could very well just have a massive vacuum leak which will throw everything out of whack.

Here is a video on testing for vacuum leaks. I love watching this guys videos:

https://www.youtube.com/watch?v=9CPqbaSgcok

[vandura95]

I would clear all the codes and see which ones come back first. then start from there.

I disconnected the +cable and let it sit an hour or so, reconnected everything and went for a short drive.
The codes do not show in the list view now.

I have concerns for the O2 sensor now, it bounces erratically from 199.00 to 800.00

7920
Advanced $0D.xdf

[uhlhazard]

Here is a video explaining o2 sensors.

https://www.youtube.com/watch?v=NIzcztO-CCs

[vandura95]

The barometric pressure is 97.8
Is this normal?

[uhlhazard]

Can you try and find out what scale the baro is using? It could be out of 100, kpa, hg, etc. I don't know how to do it myself, 97.8 is strange. I would expect 0 being WOT and 30 being complete vacuum but that is in inches of mercury.

[vandura95]

There is some good info about map sensors here.
http://www.aa1car.com/library/map_sensors.htm
7925

[uhlhazard]

Awesome find vandura!

[vandura95]

"http://www.gmtuners.com/tech/MAF_MAP_IAT.htm
"When the engine is started, the ECM uses the MAP sensor readings to determine engine load. This is the primary sensor it uses to determine fuel and spark delivery to the engine. The MAP sensor reading is factored in with engine RPM to calculate volumetric efficiency. This is known as Speed Density (engine speed and density of the air charge). Volumetric efficiency (VE) is the term used to describe the amount of air an engine is ingesting vs. the amount of air it can actually hold, expressed in a percentage. If the engine is ingesting the maximum amount of air it can hold, then that engine is considered to be operating at 100% VE. Most naturally aspirated engines never see 100% VE; but engines using specially-tuned intake manifolds can accomplish this. Of course this can also be accomplished and exceeded with a turbo or supercharger by adding boost. Most naturally aspirated engines typically see up to 80-90% VE without a tuned intake design.

Obviously if there is a problem with the MAP sensor, or the vacuum/pressure readings it is getting are not accurate, this is going to greatly affect the way the engine runs. GM MAP sensors aren’t easily prone to failure, but I have seen them fail if exposed to great pressures such as what could occur if the engine backfired thru the intake. The most common situation that I see that can cause issues with the MAP sensor is a vacuum leak. Any kind of vacuum leak will cause the pressure levels the MAP sensor sees to be lower than expected. This tends to cause the Air/Fuel mixture to go rich (because the ECM thinks the engine is under a load)."...
http://www.gmtuners.com/tech/MAF_MAP_IAT.htm"

I am not getting any codes or ses light.
Based upon the Barometric pressure reading in Tunerpro, do you think It wound be a good idea to test the MAP sensor?

[Fast355]

"http://www.gmtuners.com/tech/MAF_MAP_IAT.htm
"When the engine is started, the ECM uses the MAP sensor readings to determine engine load. This is the primary sensor it uses to determine fuel and spark delivery to the engine. The MAP sensor reading is factored in with engine RPM to calculate volumetric efficiency. This is known as Speed Density (engine speed and density of the air charge). Volumetric efficiency (VE) is the term used to describe the amount of air an engine is ingesting vs. the amount of air it can actually hold, expressed in a percentage. If the engine is ingesting the maximum amount of air it can hold, then that engine is considered to be operating at 100% VE. Most naturally aspirated engines never see 100% VE; but engines using specially-tuned intake manifolds can accomplish this. Of course this can also be accomplished and exceeded with a turbo or supercharger by adding boost. Most naturally aspirated engines typically see up to 80-90% VE without a tuned intake design.

Obviously if there is a problem with the MAP sensor, or the vacuum/pressure readings it is getting are not accurate, this is going to greatly affect the way the engine runs. GM MAP sensors aren’t easily prone to failure, but I have seen them fail if exposed to great pressures such as what could occur if the engine backfired thru the intake. The most common situation that I see that can cause issues with the MAP sensor is a vacuum leak. Any kind of vacuum leak will cause the pressure levels the MAP sensor sees to be lower than expected. This tends to cause the Air/Fuel mixture to go rich (because the ECM thinks the engine is under a load)."...
http://www.gmtuners.com/tech/MAF_MAP_IAT.htm"

I am not getting any codes or ses light.
Based upon the Barometric pressure reading in Tunerpro, do you think It wound be a good idea to test the MAP sensor?

IMO the best place to look would be the TBI base gasket if the MAP reading is suspect. A vacuum leak is common there and will greatly effect the MAP sensor function and fuel delivery.

[vandura95]

IMO the best place to look would be the TBI base gasket if the MAP reading is suspect. A vacuum leak is common there and will greatly effect the MAP sensor function and fuel delivery.

I just replaced the base gasket prior to the test, the rebuild kit came with two base gaskets. I can swap them out to see if it make a difference.
I will most likely do compression test and change the intake gasket when I get back to my shop next month.


7927

[vandura95]

The barometric pressure is 97.8
Is this normal?

In the Tuner Pro dash it reads 97.8 Barometric.
Is this a concern?

[Fast355]

In the Tuner Pro dash it reads 97.8 Barometric.
Is this a concern?

That number will vary depending on barometric pressure and altitude.

[vandura95]

I have figured out how to get the basic log recorded,
I have this loaded in Tunerpro: Advanced $0D.xdf and the BJYN for the 1995 GMC van


Should I follow the instructions in the following link now?
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?1895-Adjusting-VE-Fueling-tables-with-BLM-data-Tutorial

Should I smooth out the VE fuel in the open throttle vs map vs rpm and run another log?
I do not have the burn 2 yet. I still think I am a long way off from that point anyway.

I don't want to start another newbie thread, I'd like to just keep working off of this one.